This invention relates to the use of needle guiding adapter hardware which is attached to an ultrasound transducer for real-time visual guidance of a biopsy or aspiration needle, or catheter, into the human body to a specific target location using the ultrasound system as an aid to the physician. Medical professionals are concerned with the ease and accuracy of attachment of needle guiding devices and maintenance of a sterile environment throughout a surgical procedure. In the prior art, needle guidance devices for use with ultrasound transducers have typically utilized cumbersome threaded fasteners or bulky formed metal springs which are difficult to actuate and which can trap biohazardous materials not easily cleaned by standard methods. Some examples are U.S. Pat. Nos. 5,052,396 and 4,898,178 (Wedel, et al) and U.S. Pat. No. 4,576,175 (Epstein) which all employ screw-thread type fasteners for either closing of a clamp around or direct attachment of a needle guiding device to an ultrasound transducer. U.S. Pat. No. 5,076,279 uses a dedicated formed metal spring and roller assembly for attachment.